scripts/tracetool/__init__.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 """
   5 Machinery for generating tracing-related intermediate files.
   6 """
   7
   8 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
   9 __copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
  10 __license__    = "GPL version 2 or (at your option) any later version"
  11
  12 __maintainer__ = "Stefan Hajnoczi"
  13 __email__      = "stefanha@linux.vnet.ibm.com"
  14
  15
  16 import re
  17 import sys
  18 import weakref
  19
  20 import tracetool.format
  21 import tracetool.backend
  22 import tracetool.transform
  23
  24
  25 def error_write(*lines):
  26     """Write a set of error lines."""
  27     sys.stderr.writelines("\n".join(lines) + "\n")
  28
  29 def error(*lines):
  30     """Write a set of error lines and exit."""
  31     error_write(*lines)
  32     sys.exit(1)
  33
  34
  35 def out(*lines, **kwargs):
  36     """Write a set of output lines.
  37
  38     You can use kwargs as a shorthand for mapping variables when formating all
  39     the strings in lines.
  40     """
  41     lines = [ l % kwargs for l in lines ]
  42     sys.stdout.writelines("\n".join(lines) + "\n")
  43
  44
  45 class Arguments:
  46     """Event arguments description."""
  47
  48     def __init__(self, args):
  49         """
  50         Parameters
  51         ----------
  52         args :
  53             List of (type, name) tuples.
  54         """
  55         self._args = args
  56
  57     def copy(self):
  58         """Create a new copy."""
  59         return Arguments(list(self._args))
  60
  61     @staticmethod
  62     def build(arg_str):
  63         """Build and Arguments instance from an argument string.
  64
  65         Parameters
  66         ----------
  67         arg_str : str
  68             String describing the event arguments.
  69         """
  70         res = []
  71         for arg in arg_str.split(","):
  72             arg = arg.strip()
  73             if arg == 'void':
  74                 continue
  75
  76             if '*' in arg:
  77                 arg_type, identifier = arg.rsplit('*', 1)
  78                 arg_type += '*'
  79                 identifier = identifier.strip()
  80             else:
  81                 arg_type, identifier = arg.rsplit(None, 1)
  82
  83             res.append((arg_type, identifier))
  84         return Arguments(res)
  85
  86     def __iter__(self):
  87         """Iterate over the (type, name) pairs."""
  88         return iter(self._args)
  89
  90     def __len__(self):
  91         """Number of arguments."""
  92         return len(self._args)
  93
  94     def __str__(self):
  95         """String suitable for declaring function arguments."""
  96         if len(self._args) == 0:
  97             return "void"
  98         else:
  99             return ", ".join([ " ".join([t, n]) for t,n in self._args ])
 100
 101     def __repr__(self):
 102         """Evaluable string representation for this object."""
 103         return "Arguments(\"%s\")" % str(self)
 104
 105     def names(self):
 106         """List of argument names."""
 107         return [ name for _, name in self._args ]
 108
 109     def types(self):
 110         """List of argument types."""
 111         return [ type_ for type_, _ in self._args ]
 112
 113     def transform(self, *trans):
 114         """Return a new Arguments instance with transformed types.
 115
 116         The types in the resulting Arguments instance are transformed according
 117         to tracetool.transform.transform_type.
 118         """
 119         res = []
 120         for type_, name in self._args:
 121             res.append((tracetool.transform.transform_type(type_, *trans),
 122                         name))
 123         return Arguments(res)
 124
 125
 126 class Event(object):
 127     """Event description.
 128
 129     Attributes
 130     ----------
 131     name : str
 132         The event name.
 133     fmt : str
 134         The event format string.
 135     properties : set(str)
 136         Properties of the event.
 137     args : Arguments
 138         The event arguments.
 139
 140     """
 141
 142     _CRE = re.compile("((?P<props>[\w\s]+)\s+)?"
 143                       "(?P<name>\w+)"
 144                       "\((?P<args>[^)]*)\)"
 145                       "\s*"
 146                       "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
 147                       "\s*")
 148
 149     _VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec"])
 150
 151     def __init__(self, name, props, fmt, args, orig=None):
 152         """
 153         Parameters
 154         ----------
 155         name : string
 156             Event name.
 157         props : list of str
 158             Property names.
 159         fmt : str, list of str
 160             Event printing format (or formats).
 161         args : Arguments
 162             Event arguments.
 163         orig : Event or None
 164             Original Event before transformation.
 165
 166         """
 167         self.name = name
 168         self.properties = props
 169         self.fmt = fmt
 170         self.args = args
 171
 172         if orig is None:
 173             self.original = weakref.ref(self)
 174         else:
 175             self.original = orig
 176
 177         unknown_props = set(self.properties) - self._VALID_PROPS
 178         if len(unknown_props) > 0:
 179             raise ValueError("Unknown properties: %s"
 180                              % ", ".join(unknown_props))
 181         assert isinstance(self.fmt, str) or len(self.fmt) == 2
 182
 183     def copy(self):
 184         """Create a new copy."""
 185         return Event(self.name, list(self.properties), self.fmt,
 186                      self.args.copy(), self)
 187
 188     @staticmethod
 189     def build(line_str):
 190         """Build an Event instance from a string.
 191
 192         Parameters
 193         ----------
 194         line_str : str
 195             Line describing the event.
 196         """
 197         m = Event._CRE.match(line_str)
 198         assert m is not None
 199         groups = m.groupdict('')
 200
 201         name = groups["name"]
 202         props = groups["props"].split()
 203         fmt = groups["fmt"]
 204         fmt_trans = groups["fmt_trans"]
 205         if len(fmt_trans) > 0:
 206             fmt = [fmt_trans, fmt]
 207         args = Arguments.build(groups["args"])
 208
 209         if "tcg-trans" in props:
 210             raise ValueError("Invalid property 'tcg-trans'")
 211         if "tcg-exec" in props:
 212             raise ValueError("Invalid property 'tcg-exec'")
 213         if "tcg" not in props and not isinstance(fmt, str):
 214             raise ValueError("Only events with 'tcg' property can have two formats")
 215         if "tcg" in props and isinstance(fmt, str):
 216             raise ValueError("Events with 'tcg' property must have two formats")
 217
 218         return Event(name, props, fmt, args)
 219
 220     def __repr__(self):
 221         """Evaluable string representation for this object."""
 222         if isinstance(self.fmt, str):
 223             fmt = self.fmt
 224         else:
 225             fmt = "%s, %s" % (self.fmt[0], self.fmt[1])
 226         return "Event('%s %s(%s) %s')" % (" ".join(self.properties),
 227                                           self.name,
 228                                           self.args,
 229                                           fmt)
 230
 231     _FMT = re.compile("(%[\d\.]*\w+|%.*PRI\S+)")
 232
 233     def formats(self):
 234         """List of argument print formats."""
 235         assert not isinstance(self.fmt, list)
 236         return self._FMT.findall(self.fmt)
 237
 238     QEMU_TRACE               = "trace_%(name)s"
 239     QEMU_TRACE_TCG           = QEMU_TRACE + "_tcg"
 240
 241     def api(self, fmt=None):
 242         if fmt is None:
 243             fmt = Event.QEMU_TRACE
 244         return fmt % {"name": self.name}
 245
 246     def transform(self, *trans):
 247         """Return a new Event with transformed Arguments."""
 248         return Event(self.name,
 249                      list(self.properties),
 250                      self.fmt,
 251                      self.args.transform(*trans),
 252                      self)
 253
 254
 255 def _read_events(fobj):
 256     events = []
 257     for line in fobj:
 258         if not line.strip():
 259             continue
 260         if line.lstrip().startswith('#'):
 261             continue
 262
 263         event = Event.build(line)
 264
 265         # transform TCG-enabled events
 266         if "tcg" not in event.properties:
 267             events.append(event)
 268         else:
 269             event_trans = event.copy()
 270             event_trans.name += "_trans"
 271             event_trans.properties += ["tcg-trans"]
 272             event_trans.fmt = event.fmt[0]
 273             args_trans = []
 274             for atrans, aorig in zip(
 275                     event_trans.transform(tracetool.transform.TCG_2_HOST).args,
 276                     event.args):
 277                 if atrans == aorig:
 278                     args_trans.append(atrans)
 279             event_trans.args = Arguments(args_trans)
 280             event_trans = event_trans.copy()
 281
 282             event_exec = event.copy()
 283             event_exec.name += "_exec"
 284             event_exec.properties += ["tcg-exec"]
 285             event_exec.fmt = event.fmt[1]
 286             event_exec = event_exec.transform(tracetool.transform.TCG_2_HOST)
 287
 288             new_event = [event_trans, event_exec]
 289             event.event_trans, event.event_exec = new_event
 290
 291             events.extend(new_event)
 292
 293     return events
 294
 295
 296 class TracetoolError (Exception):
 297     """Exception for calls to generate."""
 298     pass
 299
 300
 301 def try_import(mod_name, attr_name=None, attr_default=None):
 302     """Try to import a module and get an attribute from it.
 303
 304     Parameters
 305     ----------
 306     mod_name : str
 307         Module name.
 308     attr_name : str, optional
 309         Name of an attribute in the module.
 310     attr_default : optional
 311         Default value if the attribute does not exist in the module.
 312
 313     Returns
 314     -------
 315     A pair indicating whether the module could be imported and the module or
 316     object or attribute value.
 317     """
 318     try:
 319         module = __import__(mod_name, globals(), locals(), ["__package__"])
 320         if attr_name is None:
 321             return True, module
 322         return True, getattr(module, str(attr_name), attr_default)
 323     except ImportError:
 324         return False, None
 325
 326
 327 def generate(fevents, format, backends,
 328              binary=None, probe_prefix=None):
 329     """Generate the output for the given (format, backends) pair.
 330
 331     Parameters
 332     ----------
 333     fevents : file
 334         Event description file.
 335     format : str
 336         Output format name.
 337     backends : list
 338         Output backend names.
 339     binary : str or None
 340         See tracetool.backend.dtrace.BINARY.
 341     probe_prefix : str or None
 342         See tracetool.backend.dtrace.PROBEPREFIX.
 343     """
 344     # fix strange python error (UnboundLocalError tracetool)
 345     import tracetool
 346
 347     format = str(format)
 348     if len(format) is 0:
 349         raise TracetoolError("format not set")
 350     if not tracetool.format.exists(format):
 351         raise TracetoolError("unknown format: %s" % format)
 352
 353     if len(backends) is 0:
 354         raise TracetoolError("no backends specified")
 355     for backend in backends:
 356         if not tracetool.backend.exists(backend):
 357             raise TracetoolError("unknown backend: %s" % backend)
 358     backend = tracetool.backend.Wrapper(backends, format)
 359
 360     import tracetool.backend.dtrace
 361     tracetool.backend.dtrace.BINARY = binary
 362     tracetool.backend.dtrace.PROBEPREFIX = probe_prefix
 363
 364     events = _read_events(fevents)
 365
 366     tracetool.format.generate(events, format, backend)